Title: Quantitative electroencephalography after cardiac arrest Abstract Brain injury is the most dreaded result of critical illness. For more than half a million Americans who suffer sudden cardiac arrest each year, current therapies are inadequate and outcomes are abysmal. Among more than 100,000 patients who regain pulses, severe global brain injury is common and the major driver of both morbidity and mortality. This is a major public health problem. My proposal addresses two important, potentially preventable causes of death and disability due to post-arrest brain injury. The first of these problems is secondary brain injury from ongoing tissue hypoxia and hypoperfusion in the days after resuscitation. Outcomes are further worsened by inaccurate neurological prognostication, which directly increases mortality through premature withdrawal of care in patients who might otherwise have had favorable recoveries. Quantitative electroencephalography (qEEG) is a tool that measures individual components or overall characteristics of electrical brain activity, and may help overcome both of these problems. In our first aim, we will use innovative statistical methods to determine whether qEEG can noninvasively detect brain tissue hypoxia and hypoperfusion. We already use invasive monitoring to measure brain oxygen and perfusion, providing an unprecedented opportunity to test contemporaneously acquired qEEG against accepted clinical reference standards. Identification of qEEG markers of secondary brain injury would allow early and non-invasive patient care based on individualized need and real-time response to therapy. In the second aim, we will define the ability of qEEG signatures to predict subsequent neurological deterioration and death, and test its value as one element of a multistep prognostic algorithm. Currently, accurate prognostication is optimal only days after arrest. This is burdensome for families, resource intensive and often leads to premature withdrawal of life-sustaining therapy in patients who would otherwise have awakened and been able to live independently had they been given more time to recover. This career development award will directly contribute to my long-term research goals to develop, test, and implement innovative treatment strategies that reduce the burden of preventable brain injury in the critically ill. The award will provide me with the cross-disciplinary mentored experience and training necessary to achieve these goals and become a productive independent investigator.